chr20-58840220-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2BP4_StrongBP6BP7

The NM_016592.5(GNAS):​c.114C>T​(p.Ser38=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,458,826 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (no stars).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

GNAS
NM_016592.5 synonymous

Scores

2

Clinical Significance

Likely benign no assertion criteria provided B:1

Conservation

PhyloP100: 0.642
Variant links:
Genes affected
GNAS (HGNC:4392): (GNAS complex locus) This locus has a highly complex imprinted expression pattern. It gives rise to maternally, paternally, and biallelically expressed transcripts that are derived from four alternative promoters and 5' exons. Some transcripts contain a differentially methylated region (DMR) at their 5' exons, and this DMR is commonly found in imprinted genes and correlates with transcript expression. An antisense transcript is produced from an overlapping locus on the opposite strand. One of the transcripts produced from this locus, and the antisense transcript, are paternally expressed noncoding RNAs, and may regulate imprinting in this region. In addition, one of the transcripts contains a second overlapping ORF, which encodes a structurally unrelated protein - Alex. Alternative splicing of downstream exons is also observed, which results in different forms of the stimulatory G-protein alpha subunit, a key element of the classical signal transduction pathway linking receptor-ligand interactions with the activation of adenylyl cyclase and a variety of cellular reponses. Multiple transcript variants encoding different isoforms have been found for this gene. Mutations in this gene result in pseudohypoparathyroidism type 1a, pseudohypoparathyroidism type 1b, Albright hereditary osteodystrophy, pseudopseudohypoparathyroidism, McCune-Albright syndrome, progressive osseus heteroplasia, polyostotic fibrous dysplasia of bone, and some pituitary tumors. [provided by RefSeq, Aug 2012]
GNAS-AS1 (HGNC:24872): (GNAS antisense RNA 1) This gene produces a paternally-imprinted antisense RNA transcript that helps regulate the GNAS complex locus, which encodes the alpha subunit of the stimulatory G protein. Defects in this gene are a cause of pseudohypoparathyroidism type Ib.[provided by RefSeq, Jun 2010]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.49).
BP6
Variant 20-58840220-C-T is Benign according to our data. Variant chr20-58840220-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 3349511.Status of the report is no_assertion_criteria_provided, 0 stars.
BP7
Synonymous conserved (PhyloP=0.642 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
GNASNM_016592.5 linkuse as main transcriptc.114C>T p.Ser38= synonymous_variant 1/13 ENST00000371075.7
GNAS-AS1NR_002785.2 linkuse as main transcriptn.819+1717G>A intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
GNASENST00000371075.7 linkuse as main transcriptc.114C>T p.Ser38= synonymous_variant 1/131 NM_016592.5 O95467-1
GNAS-AS1ENST00000424094.6 linkuse as main transcriptn.819+1717G>A intron_variant, non_coding_transcript_variant 1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1458826
Hom.:
0
Cov.:
35
AF XY:
0.00000138
AC XY:
1
AN XY:
725916
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000469
Hom.:
0

ClinVar

Significance: Likely benign
Submissions summary: Benign:1
Revision: no assertion criteria provided
LINK: link

Submissions by phenotype

GNAS-related disorder Benign:1
Likely benign, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesApr 17, 2024This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.49
CADD
Benign
14
DANN
Benign
0.95
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.8

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs2085663948; hg19: chr20-57415275; API